#!

# This is statement is required by the build system to query build info
if __name__ == '__build__':
    raise Exception

## Texture mapping an image--- derived mainly from texturesurf.c (SGI demo)
## Notable feature: uses PIL to load a PPM image, which is then texturemapped
## to a bezier surface, using PyOpenGL.

## Note: your image needs to be RGBA, and the image
## dimensions must be powers of two, starting
## with 64 (ie, 64x64, 128x128, etc)

## also, I noticed that from certain directions the surface is
## partially transparent.  is there a bug in my code,
## or is it the way that OpenGL handles concave surfaces?
## if you figure it out, let me know.
## (it may invlve backface culling)

## Written by David Konerding (dek@cgl.ucsf.edu)
## You are free to modify and redistribute this code.



import sys

from PIL.Image import *
from OpenGL.GL import *
from OpenGL.Tk import *



## Control points for the bezier surface
ctrlpoints = [[[-1.5, -1.5, 4.0], [-0.5, -1.5, 2.0], [0.5, -1.5, -1.0], [1.5, -1.5, 2.0]],
              [[-1.5, -0.5, 1.0], [-0.5, -0.5, 3.0], [0.5, -0.5, 0.0], [1.5, -0.5, -1.0]],
              [[-1.5, 0.5, 4.0], [-0.5, 0.5, 0.0], [0.5, 0.5, 3.0], [1.5, 0.5, 4.0]],
              [[-1.5, 1.5, -2.0], [-0.5, 1.5, -2.0], [0.5, 1.5, 0.0], [1.5, 1.5, -1.0]]]

## Texture control points
texpts = [[[0.0, 0.0], [0.0, 1.0]], [[1.0, 0.0], [1.0, 1.0]]]


class Surface:
    def Display(self, event=None):
        glClearColor(0.0, 0.0, 0.0, 0)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glCallList(self.list)

    def SetupWindow(self):
        self.OglFrame = Frame()
        self.OglFrame.pack(side='top')
        self.QuitButton = Button(self.OglFrame, {'text': 'Quit'})
        self.QuitButton.bind('<ButtonRelease-1>', sys.exit)
        self.QuitButton.pack({'side': 'top'})

    def SetupOpenGL(self):
        self.ogl = Opengl(master=self.OglFrame, width=500, height=500, double=1, depth=1)
        self.ogl.pack(side='top', expand=1, fill='both')
        self.ogl.set_centerpoint(0, 0, 0)
        self.ogl.redraw = self.Display

    ## Note: only works for RGBA images where side length is power of 2
    def MakeImage(self, filename):
        im = open(filename)
        self.imageWidth = im.size[0]
        self.imageHeight = im.size[1]
        self.image = im.tostring("raw", "RGBX", 0, -1)

        # print self.imageWidth, self.imageHeight, self.imageWidth * self.imageHeight*4, len(self.image)


    ## this hunk of code handles the bezier mapping and texture mapping
    def Surface(self):
        glDisable(GL_CULL_FACE)
        glMap2f(GL_MAP2_VERTEX_3, 0, 1, 0, 1, ctrlpoints)
        glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 0, 1, texpts)
        glEnable(GL_MAP2_TEXTURE_COORD_2)
        glEnable(GL_MAP2_VERTEX_3)
        glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0)
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
        print(type(self.image))
        glTexImage2D(GL_TEXTURE_2D, 0, 3, self.imageWidth, self.imageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, self.image)
        glEnable(GL_TEXTURE_2D)
        glEnable(GL_DEPTH_TEST)
        glEnable(GL_NORMALIZE)
        glShadeModel(GL_FLAT)

        self.list = glGenLists(1)
        glNewList(self.list, GL_COMPILE)
        glEvalMesh2(GL_FILL, 0, 20, 0, 20)
        glEndList()

    def __init__(self):
        try:
            filename = sys.argv[1]
        except:
            filename = "image.ppm"
            sys.stderr.write("usage: <name> ppmfilename\n")
        #sys.exit(1)

        self.SetupWindow()
        self.MakeImage(filename)
        self.SetupOpenGL()
        self.Surface()

        self.ogl.tkRedraw()
        self.ogl.mainloop()


if __name__ == '__main__':
    Surface()

demo = Surface
